In vehicle automatic transmissions, a smooth upshift (i.e., ratio change) between two friction elements, commonly referred to as a clutch-to-clutch shift, is a difficult task to perform consistently. The torque capacity of the oncoming friction element must be precisely synchronized to the torque capacity of the off-going friction element to produce a pleasingly smooth reduction in output torque (multiplied by the mechanical advantage of the transmission gear train) without any appreciable change in engine speed during the event. Changing characteristics, such as fluid properties, coefficients of friction between the friction elements, and temperature can negatively impact the quality of the clutch-to-clutch shift.